From bdf62302363eff157211db57b3a9688a00ad3ca4 Mon Sep 17 00:00:00 2001
From: Vinayak Kariappa Chettimada <vich@nordicsemi.no>
Date: Fri, 15 Mar 2024 12:24:33 +0100
Subject: [PATCH] samples: Bluetooth: Add LED blinking to peripheral_hr

Add LED blinking state to peripheral_hr indicating
advertising state, and LED On state to indicate connected
to a central device, respectively.

Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>
---
 samples/bluetooth/peripheral_hr/src/main.c | 92 ++++++++++++++++++++--
 1 file changed, 85 insertions(+), 7 deletions(-)

diff --git a/samples/bluetooth/peripheral_hr/src/main.c b/samples/bluetooth/peripheral_hr/src/main.c
index 938de5f01e1..03279c0840f 100644
--- a/samples/bluetooth/peripheral_hr/src/main.c
+++ b/samples/bluetooth/peripheral_hr/src/main.c
@@ -7,13 +7,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-#include <zephyr/types.h>
-#include <stddef.h>
-#include <string.h>
-#include <errno.h>
-#include <zephyr/sys/printk.h>
-#include <zephyr/sys/byteorder.h>
-#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
 
 #include <zephyr/bluetooth/bluetooth.h>
 #include <zephyr/bluetooth/hci.h>
@@ -124,6 +119,73 @@ static void hrs_notify(void)
 	}
 }
 
+#if defined(CONFIG_GPIO)
+/* The devicetree node identifier for the "led0" alias. */
+#define LED0_NODE DT_ALIAS(led0)
+
+#if DT_NODE_HAS_STATUS(LED0_NODE, okay)
+#include <zephyr/drivers/gpio.h>
+#define HAS_LED     1
+static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(LED0_NODE, gpios);
+#define BLINK_ONOFF K_MSEC(500)
+
+static struct k_work_delayable blink_work;
+static bool                  led_is_on;
+
+static void blink_timeout(struct k_work *work)
+{
+	led_is_on = !led_is_on;
+	gpio_pin_set(led.port, led.pin, (int)led_is_on);
+
+	k_work_schedule(&blink_work, BLINK_ONOFF);
+}
+
+static int blink_setup(void)
+{
+	int err;
+
+	printk("Checking LED device...");
+	if (!gpio_is_ready_dt(&led)) {
+		printk("failed.\n");
+		return -EIO;
+	}
+	printk("done.\n");
+
+	printk("Configuring GPIO pin...");
+	err = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
+	if (err) {
+		printk("failed.\n");
+		return -EIO;
+	}
+	printk("done.\n");
+
+	k_work_init_delayable(&blink_work, blink_timeout);
+
+	return 0;
+}
+
+static void blink_start(void)
+{
+	printk("Start blinking LED...\n");
+	led_is_on = false;
+	gpio_pin_set(led.port, led.pin, (int)led_is_on);
+	k_work_schedule(&blink_work, BLINK_ONOFF);
+}
+
+static void blink_stop(void)
+{
+	struct k_work_sync work_sync;
+
+	printk("Stop blinking LED.\n");
+	k_work_cancel_delayable_sync(&blink_work, &work_sync);
+
+	/* Keep LED on */
+	led_is_on = true;
+	gpio_pin_set(led.port, led.pin, (int)led_is_on);
+}
+#endif /* LED0_NODE */
+#endif /* CONFIG_GPIO */
+
 int main(void)
 {
 	int err;
@@ -193,6 +255,15 @@ int main(void)
 
 	printk("Advertising successfully started\n");
 
+#if defined(HAS_LED)
+	err = blink_setup();
+	if (err) {
+		return 0;
+	}
+
+	blink_start();
+#endif /* HAS_LED */
+
 	/* Implement notification. */
 	while (1) {
 		k_sleep(K_SECONDS(1));
@@ -206,6 +277,9 @@ int main(void)
 		if (atomic_test_and_clear_bit(state, STATE_CONNECTED)) {
 			/* Connected callback executed */
 
+#if defined(HAS_LED)
+			blink_stop();
+#endif /* HAS_LED */
 		} else if (atomic_test_and_clear_bit(state, STATE_DISCONNECTED)) {
 #if defined(CONFIG_BT_EXT_ADV)
 			printk("Starting Extended Advertising (connectable and non-scannable)\n");
@@ -215,6 +289,10 @@ int main(void)
 				return 0;
 			}
 #endif /* CONFIG_BT_EXT_ADV */
+
+#if defined(HAS_LED)
+			blink_start();
+#endif /* HAS_LED */
 		}
 	}